From: Willy Tarreau Date: Sat, 6 Jan 2007 23:18:48 +0000 (+0100) Subject: [MINOR] imported the rbtree function from Linux kernel X-Git-Tag: v1.3.5~2^2~1 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d59d22e20afb5e8734f1be24bdb804bac599b43b;p=thirdparty%2Fhaproxy.git [MINOR] imported the rbtree function from Linux kernel Those rbtree functions will be used by Sin Yu's new rbtree scheduler. --- diff --git a/include/common/rbtree.h b/include/common/rbtree.h new file mode 100644 index 0000000000..107e8d2375 --- /dev/null +++ b/include/common/rbtree.h @@ -0,0 +1,150 @@ +/* + Red Black Trees + (C) 1999 Andrea Arcangeli + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + + linux/include/linux/rbtree.h + + To use rbtrees you'll have to implement your own insert and search cores. + This will avoid us to use callbacks and to drop drammatically performances. + I know it's not the cleaner way, but in C (not in C++) to get + performances and genericity... + + Some example of insert and search follows here. The search is a plain + normal search over an ordered tree. The insert instead must be implemented + int two steps: as first thing the code must insert the element in + order as a red leaf in the tree, then the support library function + rb_insert_color() must be called. Such function will do the + not trivial work to rebalance the rbtree if necessary. + +----------------------------------------------------------------------- +static inline struct page * rb_search_page_cache(struct inode * inode, + unsigned long offset) +{ + struct rb_node * n = inode->i_rb_page_cache.rb_node; + struct page * page; + + while (n) + { + page = rb_entry(n, struct page, rb_page_cache); + + if (offset < page->offset) + n = n->rb_left; + else if (offset > page->offset) + n = n->rb_right; + else + return page; + } + return NULL; +} + +static inline struct page * __rb_insert_page_cache(struct inode * inode, + unsigned long offset, + struct rb_node * node) +{ + struct rb_node ** p = &inode->i_rb_page_cache.rb_node; + struct rb_node * parent = NULL; + struct page * page; + + while (*p) + { + parent = *p; + page = rb_entry(parent, struct page, rb_page_cache); + + if (offset < page->offset) + p = &(*p)->rb_left; + else if (offset > page->offset) + p = &(*p)->rb_right; + else + return page; + } + + rb_link_node(node, parent, p); + + return NULL; +} + +static inline struct page * rb_insert_page_cache(struct inode * inode, + unsigned long offset, + struct rb_node * node) +{ + struct page * ret; + if ((ret = __rb_insert_page_cache(inode, offset, node))) + goto out; + rb_insert_color(node, &inode->i_rb_page_cache); + out: + return ret; +} +----------------------------------------------------------------------- +*/ + +#ifndef _LINUX_RBTREE_H +#define _LINUX_RBTREE_H + +/* +#include +#include +*/ + +struct rb_node +{ + struct rb_node *rb_parent; + int rb_color; +#define RB_RED 0 +#define RB_BLACK 1 + struct rb_node *rb_right; + struct rb_node *rb_left; +}; + +struct rb_root +{ + struct rb_node *rb_node; +}; + +// Copy from linux kernel 2.6 source (kernel.h, stddef.h) +#define container_of(ptr, type, member) ({ \ + const typeof( ((type *)0)->member ) *__mptr = (ptr); \ + (type *)( (char *)__mptr - offsetof(type,member) );}) +#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER) + + +#define RB_ROOT (struct rb_root) { NULL, } +#define rb_entry(ptr, type, member) container_of(ptr, type, member) + +extern void rb_insert_color(struct rb_node *, struct rb_root *); +extern void rb_erase(struct rb_node *, struct rb_root *); + +/* Find logical next and previous nodes in a tree */ +extern struct rb_node *rb_next(struct rb_node *); +extern struct rb_node *rb_prev(struct rb_node *); +extern struct rb_node *rb_first(struct rb_root *); +extern struct rb_node *rb_last(struct rb_root *); + +/* Fast replacement of a single node without remove/rebalance/add/rebalance */ +extern void rb_replace_node(struct rb_node *victim, struct rb_node *new, + struct rb_root *root); + +static inline void rb_link_node(struct rb_node * node, struct rb_node * parent, + struct rb_node ** rb_link) +{ + node->rb_parent = parent; + node->rb_color = RB_RED; + node->rb_left = node->rb_right = NULL; + + *rb_link = node; +} + +#endif /* _LINUX_RBTREE_H */ diff --git a/src/rbtree.c b/src/rbtree.c new file mode 100644 index 0000000000..86b21badf0 --- /dev/null +++ b/src/rbtree.c @@ -0,0 +1,399 @@ +/* + Red Black Trees + (C) 1999 Andrea Arcangeli + (C) 2002 David Woodhouse + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + + linux/lib/rbtree.c +*/ + +/* +#include +#include +*/ + +#include +#include + +static void __rb_rotate_left(struct rb_node *node, struct rb_root *root) +{ + struct rb_node *right = node->rb_right; + + if ((node->rb_right = right->rb_left)) + right->rb_left->rb_parent = node; + right->rb_left = node; + + if ((right->rb_parent = node->rb_parent)) + { + if (node == node->rb_parent->rb_left) + node->rb_parent->rb_left = right; + else + node->rb_parent->rb_right = right; + } + else + root->rb_node = right; + node->rb_parent = right; +} + +static void __rb_rotate_right(struct rb_node *node, struct rb_root *root) +{ + struct rb_node *left = node->rb_left; + + if ((node->rb_left = left->rb_right)) + left->rb_right->rb_parent = node; + left->rb_right = node; + + if ((left->rb_parent = node->rb_parent)) + { + if (node == node->rb_parent->rb_right) + node->rb_parent->rb_right = left; + else + node->rb_parent->rb_left = left; + } + else + root->rb_node = left; + node->rb_parent = left; +} + +void rb_insert_color(struct rb_node *node, struct rb_root *root) +{ + struct rb_node *parent, *gparent; + + while ((parent = node->rb_parent) && parent->rb_color == RB_RED) + { + gparent = parent->rb_parent; + + if (parent == gparent->rb_left) + { + { + register struct rb_node *uncle = gparent->rb_right; + if (uncle && uncle->rb_color == RB_RED) + { + uncle->rb_color = RB_BLACK; + parent->rb_color = RB_BLACK; + gparent->rb_color = RB_RED; + node = gparent; + continue; + } + } + + if (parent->rb_right == node) + { + register struct rb_node *tmp; + __rb_rotate_left(parent, root); + tmp = parent; + parent = node; + node = tmp; + } + + parent->rb_color = RB_BLACK; + gparent->rb_color = RB_RED; + __rb_rotate_right(gparent, root); + } else { + { + register struct rb_node *uncle = gparent->rb_left; + if (uncle && uncle->rb_color == RB_RED) + { + uncle->rb_color = RB_BLACK; + parent->rb_color = RB_BLACK; + gparent->rb_color = RB_RED; + node = gparent; + continue; + } + } + + if (parent->rb_left == node) + { + register struct rb_node *tmp; + __rb_rotate_right(parent, root); + tmp = parent; + parent = node; + node = tmp; + } + + parent->rb_color = RB_BLACK; + gparent->rb_color = RB_RED; + __rb_rotate_left(gparent, root); + } + } + + root->rb_node->rb_color = RB_BLACK; +} +// EXPORT_SYMBOL(rb_insert_color); + +static void __rb_erase_color(struct rb_node *node, struct rb_node *parent, + struct rb_root *root) +{ + struct rb_node *other; + + while ((!node || node->rb_color == RB_BLACK) && node != root->rb_node) + { + if (parent->rb_left == node) + { + other = parent->rb_right; + if (other->rb_color == RB_RED) + { + other->rb_color = RB_BLACK; + parent->rb_color = RB_RED; + __rb_rotate_left(parent, root); + other = parent->rb_right; + } + if ((!other->rb_left || + other->rb_left->rb_color == RB_BLACK) + && (!other->rb_right || + other->rb_right->rb_color == RB_BLACK)) + { + other->rb_color = RB_RED; + node = parent; + parent = node->rb_parent; + } + else + { + if (!other->rb_right || + other->rb_right->rb_color == RB_BLACK) + { + register struct rb_node *o_left; + if ((o_left = other->rb_left)) + o_left->rb_color = RB_BLACK; + other->rb_color = RB_RED; + __rb_rotate_right(other, root); + other = parent->rb_right; + } + other->rb_color = parent->rb_color; + parent->rb_color = RB_BLACK; + if (other->rb_right) + other->rb_right->rb_color = RB_BLACK; + __rb_rotate_left(parent, root); + node = root->rb_node; + break; + } + } + else + { + other = parent->rb_left; + if (other->rb_color == RB_RED) + { + other->rb_color = RB_BLACK; + parent->rb_color = RB_RED; + __rb_rotate_right(parent, root); + other = parent->rb_left; + } + if ((!other->rb_left || + other->rb_left->rb_color == RB_BLACK) + && (!other->rb_right || + other->rb_right->rb_color == RB_BLACK)) + { + other->rb_color = RB_RED; + node = parent; + parent = node->rb_parent; + } + else + { + if (!other->rb_left || + other->rb_left->rb_color == RB_BLACK) + { + register struct rb_node *o_right; + if ((o_right = other->rb_right)) + o_right->rb_color = RB_BLACK; + other->rb_color = RB_RED; + __rb_rotate_left(other, root); + other = parent->rb_left; + } + other->rb_color = parent->rb_color; + parent->rb_color = RB_BLACK; + if (other->rb_left) + other->rb_left->rb_color = RB_BLACK; + __rb_rotate_right(parent, root); + node = root->rb_node; + break; + } + } + } + if (node) + node->rb_color = RB_BLACK; +} + +void rb_erase(struct rb_node *node, struct rb_root *root) +{ + struct rb_node *child, *parent; + int color; + + if (!node->rb_left) + child = node->rb_right; + else if (!node->rb_right) + child = node->rb_left; + else + { + struct rb_node *old = node, *left; + + node = node->rb_right; + while ((left = node->rb_left) != NULL) + node = left; + child = node->rb_right; + parent = node->rb_parent; + color = node->rb_color; + + if (child) + child->rb_parent = parent; + if (parent) + { + if (parent->rb_left == node) + parent->rb_left = child; + else + parent->rb_right = child; + } + else + root->rb_node = child; + + if (node->rb_parent == old) + parent = node; + node->rb_parent = old->rb_parent; + node->rb_color = old->rb_color; + node->rb_right = old->rb_right; + node->rb_left = old->rb_left; + + if (old->rb_parent) + { + if (old->rb_parent->rb_left == old) + old->rb_parent->rb_left = node; + else + old->rb_parent->rb_right = node; + } else + root->rb_node = node; + + old->rb_left->rb_parent = node; + if (old->rb_right) + old->rb_right->rb_parent = node; + goto color; + } + + parent = node->rb_parent; + color = node->rb_color; + + if (child) + child->rb_parent = parent; + if (parent) + { + if (parent->rb_left == node) + parent->rb_left = child; + else + parent->rb_right = child; + } + else + root->rb_node = child; + + color: + if (color == RB_BLACK) + __rb_erase_color(child, parent, root); +} +// EXPORT_SYMBOL(rb_erase); + +/* + * This function returns the first node (in sort order) of the tree. + */ +struct rb_node *rb_first(struct rb_root *root) +{ + struct rb_node *n; + + n = root->rb_node; + if (!n) + return NULL; + while (n->rb_left) + n = n->rb_left; + return n; +} +// EXPORT_SYMBOL(rb_first); + +struct rb_node *rb_last(struct rb_root *root) +{ + struct rb_node *n; + + n = root->rb_node; + if (!n) + return NULL; + while (n->rb_right) + n = n->rb_right; + return n; +} +// EXPORT_SYMBOL(rb_last); + +struct rb_node *rb_next(struct rb_node *node) +{ + /* If we have a right-hand child, go down and then left as far + as we can. */ + if (node->rb_right) { + node = node->rb_right; + while (node->rb_left) + node=node->rb_left; + return node; + } + + /* No right-hand children. Everything down and left is + smaller than us, so any 'next' node must be in the general + direction of our parent. Go up the tree; any time the + ancestor is a right-hand child of its parent, keep going + up. First time it's a left-hand child of its parent, said + parent is our 'next' node. */ + while (node->rb_parent && node == node->rb_parent->rb_right) + node = node->rb_parent; + + return node->rb_parent; +} +// EXPORT_SYMBOL(rb_next); + +struct rb_node *rb_prev(struct rb_node *node) +{ + /* If we have a left-hand child, go down and then right as far + as we can. */ + if (node->rb_left) { + node = node->rb_left; + while (node->rb_right) + node=node->rb_right; + return node; + } + + /* No left-hand children. Go up till we find an ancestor which + is a right-hand child of its parent */ + while (node->rb_parent && node == node->rb_parent->rb_left) + node = node->rb_parent; + + return node->rb_parent; +} +// EXPORT_SYMBOL(rb_prev); + +void rb_replace_node(struct rb_node *victim, struct rb_node *new, + struct rb_root *root) +{ + struct rb_node *parent = victim->rb_parent; + + /* Set the surrounding nodes to point to the replacement */ + if (parent) { + if (victim == parent->rb_left) + parent->rb_left = new; + else + parent->rb_right = new; + } else { + root->rb_node = new; + } + if (victim->rb_left) + victim->rb_left->rb_parent = new; + if (victim->rb_right) + victim->rb_right->rb_parent = new; + + /* Copy the pointers/colour from the victim to the replacement */ + *new = *victim; +} +// EXPORT_SYMBOL(rb_replace_node);